Cellular communication systems are widely known for mobile communication, for example in the GSM telecommunication system and the UMTS system. The UMTS system is a wideband code division multiple access (WCDMA) system according to an ITU standard derived from code-division multiple access (CDMA), and is officially known as IMT-2000 direct spread. WCDMA is a third-generation (3G) mobile wireless technology offering much higher data speeds to mobile and portable wireless devices than commonly offered in today's market. WCDMA can support mobile/portable voice, images, data, and video communications at up to 2 Mbps (local area access) or 384 Kbps (wide area access). The input signals are digitized and transmitted in coded, spread-spectrum mode over a broad range of frequencies. A 5 MHz-wide carrier is used, compared with 200 kHz-wide carrier for narrowband CDMA. Further detailed description of the WDCMA system can be found in the (proposed) technical standardization documents for the UMTS system, e.g. in the document NBAP TS 25.433 available from the website of the 3G partnership project (http://www.3gpp.org/).
An example of configuration control in a radio network telecommunication system is known from the patent application WO01/41492. A telecommunications system employing WCDMA technology is described, which utilizes compressed mode techniques to allow a mobile station to take measurements on another frequency in preparation for inter-frequency transfer. The configuration of the radio links, i.e. the selected transmission mode, coding, frequency, bandwidth, etc., has to be known both to the transmitter and to the receiver. For controlling the configuration of the radio links the assumption was that the compressed mode characteristics in a transmission slot were controlled by the network, but such control leads to problems when one considers that the slot characteristics are very dependent upon the mobile station characteristics. In the document, the control of the slot specifications are dictated by the mobile station to the network and acknowledged by the network to the mobile station. Thereafter, the network informs the WCDMA base station of the slot specifications, which are then imposed from the WCDMA base station to the mobile station. Once the mobile station receives the slot from the WCDMA base station, the mobile station is confident that the slot will conform to the characteristics that the mobile station needs in order to make the appropriate measurements.
It is to be noted that in general configuration changes, for example adding a radio link, may be effected directly by issuing change commands. However, for complex changes of the configuration such as compressed mode, there is a need for a time interval between the network deciding that a next configuration state is to be set, and the actual activation of the next configuration. In particular several involved communication elements (mobile units and/or base stations), which are operating according to a current configuration state, need to be informed of the upcoming change, because they need some time to prepare for the next configuration state.
In the existing UMTS system, there is, according to NBAP TS 25.433, provided a reconfiguration process to engage a next configuration state at a selected future time. A synchronization time counter is maintained in the communication elements, indicating time codes for synchronizing configuration changes and further time-dependent functions. However, after the involved communication elements have been informed about the reconfiguration process, further configuration changes, which relate to communication elements in the system that are not aware of the reconfiguration process, have to be postponed until after said selected future time.